Abstract
ABSTRACTThe motion of structural components in alkali silicates has been studied using molecular dynamic simulations. The relevant time correlation functions have been recorded over periods of up to 0.5 nanoseconds. The van Hove correlation functions reveal that alkali cation diffusion occurs by hopping between rather well defined sites, even at temperatures far above the melting point. The accessibility of such sites is controlled by the relaxation of the surrounding network, and constitutes the mechanism of coupling between the motion of network and modifier elements. The intermediate scattering functions exhibit a stretched exponential behavior, with a wavevector dependent stretching exponent. This is the result of a distribution of residence times at individual cation sites. When the diffusion process is examined on a coarser scale, at which Brownian motion is applicable, this distribution remains undetected. As an alternative to the Kohlrausch function, several mechanistic approaches for describing the relaxation behavior of these structures are discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
